https://community.cisco.com/t5/network-security/5525-x-and-5510-failover/m-p/3720570#M11875 <P>Hardware and software for the both units to be same always</P> Sun, 07 Oct 2018 09:44:08 GMT balaji.bandi 2018-10-07T09:44:08Z https://community.cisco.com/t5/network-security/5525-x-and-5510-failover/m-p/3720515#M11864 <P>Dear All, I have a 5525 X with firepower running in the network. I am thinking of adding a failover device as I have a 5510 ASA in stock. Can I do this configuration? What are the requirements ? Thanks</P> Fri, 21 Feb 2020 16:19:52 GMT https://community.cisco.com/t5/network-security/5525-x-and-5510-failover/m-p/3720515#M11864 mrehman02 2020-02-21T16:19:52Z https://community.cisco.com/t5/network-security/5525-x-and-5510-failover/m-p/3720525#M11868 <P>That won't work. Cisco ASA high availability pairs must be comprised of two units of the same model.</P> Sun, 07 Oct 2018 06:47:02 GMT https://community.cisco.com/t5/network-security/5525-x-and-5510-failover/m-p/3720525#M11868 Marvin Rhoads 2018-10-07T06:47:02Z https://community.cisco.com/t5/network-security/5525-x-and-5510-failover/m-p/3720570#M11875 <P>Hardware and software for the both units to be same always</P> Sun, 07 Oct 2018 09:44:08 GMT https://community.cisco.com/t5/network-security/5525-x-and-5510-failover/m-p/3720570#M11875 balaji.bandi 2018-10-07T09:44:08Z